Abaddon the Despoiler

Veil of Time — Whenever this creature attacks, you may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of attacking creatures.

You can't cast Rakdos unless an opponent lost life this turn.

Flying, trample

Creature spells you cast cost less to cast for each 1 life your opponents have lost this turn.

Haste

The Howling Abomination has trample as long as you've cast three or more spells this turn.

Whenever The Howling Abomination becomes the target of a spell, it gets +2/+2 until end of turn and deals 2 damage to each opponent.

Trample

Whenever this creature deals combat damage to a player, look at the top card of your library. You may play a land from the top of your library or cast a spell with mana value less than or equal to the damage dealt from the top of your library without paying its mana cost. If you don't, put that card into your hand.

Blitz

Indestructible

Whenever Kotis deals combat damage to a player, exile the top X cards of their library, where X is the amount of damage dealt. You may cast any number of spells with mana value X or less from among them without paying their mana costs.

, : Another target creature you control gains flying and lifelink until end of turn.

At the beginning of your end step, if you gained life this turn, exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost if the spell's mana value is less than or equal to the amount of life you gained this turn. Otherwise, put it into your hand.